The heads of metal tanks are frequently provided with resilient supporting skirts made of rubber or plastic material. The skirts aid in cushioning the tank during handling, preventing sliding movement of the tank during transporting and also serve to prevent sparking as the metal tank is slid across a surface.
With non-pressurized tanks, such as used with soft drink syrup, a metal ring carrying a resilient skirt, is welded directly to the tank head. A construction of this type is shown in U.S. Pat. No. 4,372,458.
With tanks adapted to contain pressurized fluids, such as propane and other gases, heat treating of the tank is required and the metal ring that carries the resilient skirt cannot be welded directly to the tank before heat treating because the elevated heat treating temperatures would destroy the rubber skirt. Conversely, the metal ring carrying the rubber skirt cannot be welded to the tank after heat treatment because the welding would destroy the heat treated properties of the tank. U.S. Pat. No. 4,511,055, discloses a manner of attaching a resilient skirt to a pressurized tank. In that patent a series of threaded studs are welded to the head of the tank prior to heat treatment, and after heat treatment, the metal ring that carries the resilient skirt is secured to the studs.